Studies of pair bonding behavior in the monogamous prairie vole have allowed for excellent advances in our understanding of the neurobiology of social attachment. My previous research has used behavioral pharmacology to demonstrate that dopamine (DA) transmission within the nucleus accumbens (NAc) shell is critical for pair bonding. Specifically, my work suggests that during pair bond formation, DA concentration is increased in a manner sufficient to activate high affinity D2-like receptors but not low affinity D-like receptors. Conversely, my previous behavioral pharmacology data also suggest that pair bond maintenance must be associated with high concentration phasic DA release events capable of activating D1-like receptors. Thus, pharmacological studies suggest that specific DA transmission dynamics during social behavior may regulate pair bonding behavior. However, because no prairie lab has ever had the capability to measure real-time DA transmission dynamics, our understanding of in vivo DA transmission during social bonding are quite limited. Here, we will employ fast-scan cyclic voltammetry (FSCV) to provide the first ever sub-second measurements of fluctuations in DA concentration within the NAc shell (and core) of prairie voles during social interactions with known regulation by specific DA receptor subtypes. These studies will test the hypothesis that DA regulation of pair bonding behavior is mediated by presynaptic or postsynaptic mechanisms. Findings from the proposed studies promise to represent significant advances specifically for understanding the neurobiology of social attachment. Additionally, since prairie vole pair bonding represents an ethologically sound form of motivated behavior and motivational learning, these studies will also be of significant importance to our general understanding of the neuroscience of incentive motivation, reward learning, and therefore psychological disorders associated with impairments in social/motivational behaviors regulated by mesolimbic DA transmission.